1. Field of the Invention
The present invention relates to an apparatus for finishing an inside diameter of a work, which is designed to finish inner surfaces of a plurality of bores to be finished, which are provided in the work and have diameters different from one another and axes parallel to one another, and to measure inside diameters of the bores after completion of the finishing treatment.
2. Description of the Related Art
Such an apparatus has been already known, for example, from Japanese Patent Application Laid-open No.10-217012 and the like.
In the above known apparatus, however, spindles and tools individually corresponding to a plurality of bores to be finished provided in the work are provided for each of a plurality of works, so that the finishing treatments of the plurality of works are conducted simultaneously. For this reason, when the type of the work is changed, a large number of operations of exchanging the tools on the spindles must be carried out. Therefore, the above apparatus is not suitable for the finishing treatment for multiple types of works. Moreover, after completion of the finishing treatment, each of the works is transported to a measuring station by use of a large-sized loader, resulting in an increased equipment cost.
Accordingly, it is an object of the present invention to provide an apparatus for finishing an inside diameter of a work, which is designed at a low cost to accommodate a variation in type of the work in a simple manner in carrying out the finishing treatment of a plurality of works each having a plurality of bores to be finished, which bores have different diameters, and in conducting the measurement of the diameters of the finished bores.
To achieve the above object, according to a first aspect and feature of the present invention, there is provided an apparatus for finishing an inside diameter of a work, in which inner surfaces of a plurality of bores to be finished, which are provided in the work and have diameters different from one another and axes parallel to one another, are subjected to a finishing treatment, and after completion of the finishing treatment, inside diameters of the bores are measured, the apparatus comprising a retaining frame for retaining a plurality of works at distances in a direction of an X-axis perpendicular to the axis of each of the bores to be finished, a movable table which is movable in the direction of the X-axis, a single spindle having an axis parallel to the axis of each of the bores and disposed on the movable table for advancing and retracting movements in an axial direction, a combination tool mounted at a tip end of the spindle and capable of doing the finishing treatment to the inner surfaces of the bores in accordance with a change in position of the tool inserted into each of the bores, and a measuring means which is capable of being inserted into each of the finished bores to measure an inside diameter of each of the finished bores, the measuring means being disposed on the movable table at a location displaced in the direction of the X-axis from the spindle, and capable of being be advanced and retracted in a direction along the axis of each of the bores independently from the spindle.
With such arrangement of the first feature, the plurality of works are supported side by side in the direction of the X-axis on the retaining frame. The inner surfaces of the plurality of bores provided in each of the works can be finished by the combination tool mounted at the tip end of the spindle by moving the movable table in the direction of the X-axis and axially advancing and retracting the single spindle on the movable table. If the type of the work is changed, only exchanging the combination tool is needed. Therefore, it is possible to accommodate the change in type of the work in a simple manner. Moreover, the measuring means capable of measuring the inside diameter of each of the bores is disposed at the location displaced in the direction of the X-axis from the spindle on the movable table for advancing and retraction movements independent from the spindle in the direction along the axis of the each of the bores. Therefore, when the finishing treatment of a certain work is being conducted by the combination tool, an inside diameter of a finished bore provided in another work can be measured. Thus, as compared with the prior art apparatus in which a work is transported to a measuring station by use of a large-sized loader, the time taken till the completion of the measurement can be shortened, and such a large-sized loader is not required, leading to a reduction in equipment cost.
According to a second aspect and feature of the present invention, in addition to the first feature, the apparatus further includes a correcting means provided on the spindle and capable of regulating the position of the combination tool in the radial direction of the spindle, a tool stocker in which a plurality of the combination tools are stocked in a manner that the combination tools can be alternatively brought into a previously established exchanging position at which the spindle can be moved and a combination tool removed from the tip end of the spindle can be newly retained, a deflection detector for detecting a deflection of the combination tool newly mounted at the tip end of the spindle in the exchanging position, a tool mounting and removing unit for carrying out the removal of the combination tool from the tip end of the spindle and the mounting of a combination tool to the tip end of the spindle in the exchanging position, a tool cleaning means equipped on the tool stocker and capable of cleaning that portion of one combination tool retained in the tool stocker, which is to be mounted to the spindle, a spindle cleaning means equipped on the tool stocker and capable of cleaning the tip end of the spindle, and a control means for controlling the operations of the correcting means, the tool stocker, the tool mounting and removing unit, the tool cleaning means and the spindle cleaning means as to regulate the position of the combination tool by the correcting means, based on a detection result provided by the deflection detector after the exchange of the tool in the exchanging position, or to carry out the cleaning by the tool cleaning means and the spindle cleaning means.
With such arrangement of the second feature, in a state in which the spindle has been moved to the exchanging position, the combination tool removed from the spindle by the tool mounting and removing unit can be newly retained in the tool stocker, and in a state in which one of the plurality of combination tools stocked in the tool stocker has been brought into the exchanging position, the new combination tool can be equipped on the tip end of the spindle by the tool mounting and removing unit. Moreover, when it is determined, as a result of detection of the deflection of the combination tool by the deflection detector after exchange of the combination tool, that the combination tool has been deflected largely to such an extent that the deflection can be dealt with by the correction provided by the correcting means, the correcting means can be operated to regulate the position of the combination tool in the radial direction of the spindle. When it is determined that the combination tool has been deflected largely to such an extent that it is difficult to deal with the deflection by the correction provided by the correcting means, it is determined that the incorporation of chips or the like has been caused, whereby the combination tool is removed from the spindle, and the equipped portion of the combination tool on the spindle and the tip end of the spindle are cleaned by the operation of the tool cleaning mans and the spindle cleaning means. Thereafter, the new combination tool can be equipped on a good accuracy by carrying out the exchange of the combination tool again. In this way, the automatic exchange of the combination tool is ensured, while confirming the accuracy of equipping of the combination tool on the tip end of the spindle and hence, the combination tool can be exchanged automatically, while avoiding a reduction in finishing accuracy.
According to a third aspect and feature of the present invention, in addition to the second feature, the tool stocker includes a rotor rotatable about an axis parallel to the axis of the spindle, tool grasping means which are disposed at a plurality of points equally spaced from one another in a circumferential direction of the rotor, excluding one point at which the spindle cleaning means is disposed, each of the tool grasping means being capable of releasably grasping the combination tool, and a rotor driving means for driving the rotor in such a manner to bring the tool grasping means and the spindle cleaning means alternatively into the exchanging position.
With such arrangement of the third feature, the plurality of tool grasping means for releasably grasping the combination tools and the spindle cleaning means can be alternatively brought into the exchanging position. Therefore, one of the plurality of combination tools can be selected and equipped on the tip end of the spindle by moving the tip end of the spindle to the exchanging position, and the combination tool removed from the tip end of the spindle can be stocked in the tool stocker. When the tip end of the spindle is stained, the tip end of the spindle can be cleaned automatically by bringing the spindle cleaning means to the exchanging position.
According to a fourth aspect and feature of the present invention, in addition to the second feature, the spindle is provided at its tip end with a cam clamp mechanism which includes a clamp bolt rotatable about an axis perpendicular to the rotational axis of the spindle and which is capable of being switched over between a clamping state of clamping the composition tool provided by rotating the clamp bolt in a normal direction, and an unclamping state of unclamping the composition tool provided by rotating the clamp bolt in a reverse direction, and the tool mounting and removing unit includes a moving member reciprocally movable in a direction perpendicular to the rotational axis of the spindle in the exchanging position, a moving member driving means for reciprocally moving the moving member, a rotary shaft carried on the moving member for rotation about an axis perpendicular to the rotational axis of the spindle, a wrench which is coaxially connected at a base end thereof to one end of the rotary shaft against relative rotation about the axis of the rotary shaft but for relative movement in a limited region in an axial direction of the rotary shaft, the wrench being capable of being brought into engagement with a tip end of the clamp bolt, a spring mounted under compression between the base end of the wrench and the one end of the rotary shaft, and a rotary shaft driving means capable of rotating the rotary shaft in either of normal and reverse directions irrespective of the moved position of the moving member, and the operations of the moving member driving means and the rotary shaft driving means are controlled by the control means, based on detection results provided by an engaged-state detector for detecting whether the tip end of the wrench has been brought into engagement with the clamp bolt, in accordance with the axial relative positions of the rotary shaft and the wrench, a rotation-number detector for detecting a number of rotations of the wrench in the reverse direction and an output torque detector for detecting an output torque in the normal direction from the rotary shaft driving means.
With such arrangement of the fourth feature, to remove the combination tool from the tip end of the spindle, first, the moving member is moved toward the cam clamp mechanism by the moving member driving means in a state in which the cam clamp mechanism at the tip end of the spindle has been brought into the exchanging position, and the tip end of the wrench is brought into engagement with the clamp bolt. In this case, when the engagement of the tip end of the wrench with the clamp bolt has been failed, the axial relative positions of the rotary shaft and the wrench are changed. Therefore, the reliable engagement of the wrench with the clamp bolt can be confirmed by detecting the failure of the engagement by the engaged-state detector. After confirmation of the engagement of the wrench with the clamp bolt, the cam clamp mechanism can be brought into the unclamping state by operating the rotary shaft driving means in the reverse direction. When a predetermined number of rotations has been detected by the rotation-number detector, the operation of the rotary shaft driving means is stopped, and the moving member is moved in a direction away from the cam clamp mechanism by the moving member driving means. This releases the engagement of the wrench with the clamp bolt, whereby the wrench is moved away from the cam clamp mechanism. To newly mount the combination tool to the tip end of the spindle, the moving member is moved toward the cam clamp mechanism which is in the exchanging position, and the tip end of the wrench is brought into engagement with the clamp bolt. It is detected by the engaged-state detector that the tip end of the wrench has been engaged with the clamp bolt, and then, the rotary shaft driving means is operated in the normal direction. In this manner, the cam clamp mechanism can be brought into the clamping state. When a predetermined torque has been detected by the torque detector, the operation of the rotary shaft driving means is stopped, and the moving member is moved in the direction away from the cam clamp mechanism by the moving member driving means. This releases the engagement of the wrench with the clamp bolt, whereby the wrench is moved away from the cam clamp mechanism. In this manner, the clamping state and the unclamping state of the cam clamp mechanism can be switched over automatically from one to another, thereby enabling the automatic mounting and removal of the combination tool to and from the tip end of the spindle.
According to a fifth aspect and feature of the present invention, in addition to the first feature, the apparatus further includes a first positioning means capable of being switched over between a locking state in which it is put into abutment against an inner surface of a smaller-diameter bore provided as a bore to be finished in a smaller end of a connecting rod as a work at a plurality of circumferential points, thereby positioning the smaller end, and an unlocking state in which the positioning of the smaller end is released at the finishing treatment of the smaller-diameter bore, whereby the first positioning means is retracted from the smaller-diameter bore, a second positioning means capable of being switched over between a locking state in which it is put into abutment against an inner surface of a larger-diameter bore provided as a bore to be finished in the connecting rod at a plurality of circumferential points, thereby positioning the larger end, and an unlocking state in which the positioning of the larger end is released at the finishing treatment of the larger-diameter bore, whereby the second positioning means is retracted from the larger-diameter bore, and a clamp means capable of urging the connecting rod, with the larger and smaller ends put into abutment against reference support faces, toward the reference support faces to retain the connecting rod on the retaining frame.
With such arrangement of the fifth feature, the first and second positioning means are brought into abutment against the inner surfaces of the smaller-diameter and the larger-diameter bores at the pluralities of points to position the smaller and larger ends, respectively. Therefore, even if the connecting rod is an as-cast product, the connecting rod with the larger and smaller ends put into abutment against the reference support faces can be positioned precisely, and the connecting rod in the precisely positioned state can be retained on the retaining frame by the clamp means.
According to a sixth aspect and feature of the present invention, in addition to the fifth feature, the first positioning means comprises a guide member releasably fixed to the retaining frame and having the reference support face against which the smaller end of the connecting rod is put into abutment, a holder which is formed into a cylindrical shape, so that one end thereof can be coaxially inserted and removed into and out of the smaller-diameter bore, and whose axial movement is guided by the guide member, a plurality of steel balls retained at one end of the holder for movement in a radial direction of the holder, a tapered pin which has, at one end thereof, a tapered face for pushing up the steel balls radially outwards to put the steel balls against the inner surface of the smaller-diameter bore at a plurality of points, the tapered pin being axially relatively movably and coaxially inserted into the holder, and a rotation-inhibiting means provided between the guide member and the holder to inhibit the rotation of the holder about an axis, the holder being connected at the other end thereof to a holder drive member provided on the retaining frame for axial reciprocal movement in a direction along the axis of the smaller-diameter bore and against rotation about the axis of the smaller-diameter bore, so that the holder can be switched over between a connected state in which the axial movement of the holder relative to the holder drive member is inhibited, and a disconnected state in which the connected state is released by rotating the holder in a predetermined amount from the connected state about the axis relative to the holder drive member, the retaining frame having a pin drive member provided thereon for axial reciprocal movement in a direction along the axis of the smaller-diameter bore and connected to the other end of the tapered pin to coaxially abut against the other end of the tapered pin.
With such arrangement of the sixth feature, the guide member, the holder guided in axial reciprocal movement by the guide member, the plurality of steel balls retained by the holder and the tapered pin axially relatively movably inserted into the holder are prepared as a single unit for every type of the work. Thus, the unit can be exchanged easily and promptly in accordance with a change in type of the work. More specifically, the connection and disconnection of the holder to and from the holder drive member can be switched over from one to another by rotating the holder about the axis in a state in which the fixing of the guide member to the retaining frame has been released. When the holder has been connected to the holder drive member, the connection and disconnection of the tapered pin to and from the pin drive member can be switched over from one to another by putting the pin drive member into coaxial abutment against the tapered pin. Moreover, the connection of the holder drive member and the holder with the guide member fixed to the retaining frame can be reliably maintained by inhibiting the rotation of the holder about the axis by the rotation inhibiting means, and accordingly, the abutting connection of the pin drive member and the tapered pin can be reliably maintained.
According to a seventh aspect and feature of the present invention, in addition to the fifth feature, the apparatus further includes a natural lock means capable of being switched over between a state in which an outer side of either one of the larger and smaller ends is resiliently retained, so that it can be released by a human""s power, and a state in which an outer side of either one of the larger and smaller ends is fixedly retained. With such arrangement, when the connecting rod is positioned, the operator""s load can be alleviated by resiliently retaining either one of the larger and smaller ends by the natural lock mans. When either one of the larger and smaller ends is being subjected to the finishing treatment, the misalignment of the connecting rod due to a force caused by such processing can be prevented by the natural lock mans.
According to an eighth aspect and feature of the present invention, in addition to the seventh feature, a mounting and removing position for carrying out the mounting and removal of the connecting rod and a processing position for carrying out the finishing treatment of the larger-diameter and smaller-diameter bores are established on opposite sides of the retaining frame which is rotatable through every 180 degrees about a horizontal rotational axis; a pair of the reference support faces against which the larger and smaller ends can be brought into abutment, a pair of the first positioning means, a pair of the clamp means and the natural lock means are disposed symmetrically with respect to the horizontal rotational axis on a side of the retaining frame facing to the mounting and removing position and on a side of the retaining frame facing the processing position; a pair of the second positioning means are disposed in the mounting-removing position; and the retaining frame is provided with a positioning drive means for commonly driving both of the first positioning means symmetrical with respect to the rotational axis in such a manner that one of the first positioning means in the mounting and removing position is brought into the locking state and the other first positioning means in the processing position is brought into the unlocking state, and a natural lock driving means for commonly driving both of the natural lock means symmetrical with respect to the rotational axis in such a manner that one of the natural lock means in the mounting-removing position is brought into the unlocking state and the other natural lock means in the processing position is brought into the locking state.
With such arrangement of the eighth feature, in the mounting and removing position, the connecting rod with the smaller and larger ends in abutment against the reference support faces can be positioned in such a manner that the smaller and larger ends are positioned by the first and second positioning means in a state in which the larger end has been retained by the natural lock means in the unlocking state. In this case, the operator""s load can be alleviated in the positioning of the connecting rod by resiliently retaining the larger end by the natural lock means. In addition, the smaller and larger ends are positioned in abutment against the inner surfaces of the smaller-diameter and larger-diameter bores at the pluralities of points, respectively, and hence, even if the connecting rod is an as-cast product, the connecting rod with the larger and smaller ends in abutment against the reference support faces can be positioned precisely. After completion of the positioning of the connecting rod by the first and second positioning means, the connecting rod can be fixedly retained on the retaining frame by the clamp means, and after retaining of the connecting rod by the clamp means, the retaining frame can be turned through 180 degrees to bring the connecting rod to the processing position by bringing the second positioning means into the unlocking state. On the other hand, in the processing position, the finishing treatment of the smaller-diameter and larger-diameter bores can be carried out by bringing the first positioning means into the unlocking state in a state in which the connecting rod has been retained on the retaining frame by the clamp means, and the misalignment of the connecting rod can be prevented from being produced by a force applied to the connecting rod by such finishing treatment, by the natural lock means in the locking state. Moreover, when the processing of the connecting rod is being conducted in the processing position, the removal of the treated connecting rod from the retaining frame and the positioning and retaining of the new connecting rod on the retaining frame can be carried out in the mounting and removing position. Therefore, the operator can mount and remove the connecting rod easily without loss in time required for mounting and removal of the connecting rod in a continuous processing cycle for the connecting rods. Thus, a reduction in equipment cost can be provided, because the mounting and removing operation by the operator is possible, as described above. Further, since the pair of first positioning means are driven by the common positioning drive means, and the pair of natural lock means are driven by the common natural lock drive means, the number of parts can be reduced.
According to a ninth aspect and feature of the present invention, in addition to the eighth feature, one of the clamp means comprises a clamper which is provided at one end of a clamp arm carried on the retaining frame for upward and downward movement about an axis parallel to the horizontal rotational axis of the retaining frame, the clamper abutting against the connecting rod, and a clamp driving cylinder is connected to the other end of the clamp arm to drive the clamp arm upwards and downwards, the clamp means and the clamp driving cylinder being mounted on the retaining frame in such an arrangement that the clamper is located above the clamp driving cylinder in the mounting and removing position and below the clamp driving cylinder in the processing position. With such arrangement, in the processing position, chips produced by the processing can be prevented to the utmost from being accumulated on the clamp arm and the clamp driving cylinder, thereby inhibiting arising of a trouble due to the chips.